import unittest


class TestIfElse(unittest.TestCase):

    def test_if_else(self):
        a = 1
        while a < 20:
            if a < 5:
                print(a, "小于5")
            elif a < 10:
                print(a, "大于等于5且小于10")
            else:
                print(a, "大于等于10")
            a += 1


if __name__ == '__main__':
    unittest.main()
